The zeolite LTA is used as an adsorbent for separations. A nitrogen adsorption study of LTA was performed (0 °C, PN₂= 760 mmHg). Using the BET plot below, calculate the specific surface area (in units of m²/g) of the zeolite. The density and molecular weight of N₂ are 0.808 g/cm³ and 28 g/mol, respectively. Assume nitrogen is a sphere with the projected surface area a (cm²/molecule). Recall that the molar volume of an ideal gas at STP is 22,400 cm³/mol.

nitrogen. 25.20 Determine the total nitrogen concentration in mg/L of a water sample containing 1.3 mg/L ammonia, 0.25 mg/L nitrite, 15.1 mg/L nitrate, and 0.9 mg/L organic nitrogen.

1.6 Properties: Diffusivity Estimate the molecular diameter and diffusion coefficient for the proteins ribonuclease (MW 13,700 Da), hemoglobin (MW 68,000), and urease (MW 480,000), assuming the molecules are spherical and the density of each protein molecule is 1.3 g/cm³.

An Al-4.5wt%Cu alloy has a low-temperature yield stress of 600 MPa due to the precipitation strengthening effect imparted by the equilibrium q phase (Al2Cu) precipitates. Estimate the interparticle spacing and particle size in this alloy. Given: density of α-solid solution 2,700 kg/m3 and density of q phase 4,430 kg/m3. Assume the Cu content in α-solid solution 0.5 wt% and the Cu content in the q phase 54%.   Hint: You need to use the Orowan model of particle strengthening and the lever rule among other concepts.